Shutter Off

[John Sharaf]

Linda,

At 24 fps with shutter off, the exposure is 1/24th of a second, with shutter on at 180 degrees it’s 1/48th of a second, effectively one stop difference. The Varicam allows you to describe the shutter speed either as a fraction of a second (like a still camera) or in degrees, which is the normal method used in a cine camera. They do this to add a comfort factor for film guys using HD cameras as replacement for their motion picture camera, and who are used to descibing shutter settings this way.

At different frame rates, both the fractional shutter speed and the speed measured in degrees of shutter result in different numbers. The manual presumes you understand either or both concepts, and merely ennuciates the procedures involved in setting the required speed. For example at 60 fps, the wide open (or shutter off) setting would be 1/60th or a second, with the shutter on and set at 180 degrees it would be 1/120th of a second.

While most film cameras use 180 degrees, some use a slightly wider shutter, such as 210 degrees. This increases both the blurred effect of each frame and opens the exposure another little bit. You might try this setting as an alternative for a film look.

JS

[Dale Mccready]

When shooting standard film speeds of 24/25FPS using 172.8 degrees and 180 dgrees is normal to achieve an exposure interval of 1/48 or 1/50th of a second. Phew. That was long winded. Anyhoo, 1/48th and 1/50th are standard motion picture frame intervals, and they give you the motion blur that you would expect to see from a film camera >The very cool thing that the Varicam can do is shoot with an open or off shutteror 0 or 360 degree shutter. Turning it off increases the exposure interval to 1/24th or 25th of a second and lets a stop more light through. Wait…come back!…What makes this cool is that you can shoot at 50FPS and instead of effectively reducing your shutter angle to 1/100th of a second you can open the shutter and still get a 1/48 or 1/50th of a second interval and the same motion blur. Smoother Slo mo as a result. Also instead of taking a hit of a stop when you shoot at 50FPS you can turn the shutter off and have the same shooting stop. Easy-peasy! No getting out the bigger lights for slo mo.